Cylinder Puzzle - Finished Weekend Project!

[raynerd]

I was browsing the net a few weeks ago and came across an engineering puzzle, the restricted nut, reasonably impressed with that but disappointed that it was actually a cheat rather than a puzzle, I started searching for potential engineering puzzles maybe even for my dad`s Christmas present - I like to make him something if I can (he is one of the only people who appreciate time spent engineering). I came across a smart little puzzle, it was an aluminium cylinder in which you had to remove the top...obviously something was restricting it. The website I found, the bloke had just made a recent post mentioning that he had cracked the puzzle after a few weeks of trying!! I emailed him and asked if he could tell me any more about the puzzle and he replied very willing to help me out. It took a while but I eventually got the concept in my head and started to draw up plans...

EDIT: I have since found the inventor of this puzzle is William Strijbos
http://www.puzzleworld.org/puzzleworld/toc.asp?t=_des/ws001.htm&m=des/ws000.htm
So, without further a do, here is the Cylinder Puzzle!    

PUZZLE: The aim is to remove the lid. The lid lifts about 1mm and can be pushed down but clearly a spring is lifting it back up. There is a hole in the bottom of the cylinder, about 6mm and ball bearings can be heard rattling around inside at various times! If the lid is depressed more ball bearings can be heard rolling. When the lid is not depressed most ball bearings appear to be trapped and can no longer be heard.

SOLUTION: ---REMOVED ---

CAD PLANS
I`m totally new to CAD so this was my best effort! If there is anything wrong or bits are drawn incorrectly, I appologise. I really enjoyed building my parts from my own neat plans!!

SORRY PLANS REMOVED.  

So I started with this 50mm bar of ally I`d had for a while!


Started turning it down to 40mm for the cylinder base piece:


I`m still not getting on with parting, so once it was down to about 42mm I took it over to the saw and hacked a piece off:


Turned it down to size, faced it up, drilled and then started to bore out the centre:



Put it on an arbour and started to clean and polish it up:


Also drilled the little 6mm window hole at the bottom. This really has no use other than to show the ball bearings from time to time.


OK ! Forgot to take a picture of the internal groove as I was getting a bit frustrated. I had to make a new tool which took some time and then after all that never took a photo! I`ve also drilled the semi-circle at the top directly into the groove.


REMOVED

Idea of size:


Then suddenly thought I better think of a spring so grabbed my box of springs and found this which was a perfect 23mm diameter and fit into the bore perfectly!


Started doing the top section - drilled to support it with the centre which isn`t in for some reason in this photo:


Opened out the centre bore:


Started to cut the groove in the core of the top:


The top section, still stuck on the huge bar! So part it off? Nope, back over to my hacksaw!


Then took the top section down to size and polished it up:


REMOVED

All the pieces plus 2 of the 4 ball bearings. To be honest, it works of course with just one but 4 makes it more difficult. I`ve only been putting 2 in for now! It still takes ME a few minutes to open it.
REMOVED
Top and bottom sections - spring lifts it to this height when you do get the satisfying pop when it opens!

IMG REMOVED

Just a little shot showing the ball bearings in the bottom window:


And here it is, locked and loaded! It is quite a challange getting it loaded. You just do it all in reverse of course and make sure you can`t see any bearings in the centre core, they all should be locked into the groove. The spring also serves in locking the balls up into the groove which means you actively have to be playing with the puzzle to have any chance and of course the lid must be depressed to align the grooves and allow the balls to rotate.




Finally, I`m going to give it one more polish and then take it to the engravers. I am going to give it my dad for Christmas and so I`ll have his initials with 2010 engraved. I`ll have one engraving on the top piece side aligned with the top groove and then one engraving on the bottom piece, 180 deg from the bottom hole. So the engravings will also have a bearing on the solution which should add a nice little addition. Pictures of that when it is done.

Well hope you enjoyed it. It works really well and it would be nice to see a few more made!! Literally took me a few hours although that isn`t including the time taken for the tool to make the internal bore. I`m going to order some smaller bearings and make a baby one out of brass. I think they are a real talking point. ... and if anyone could find the time to knock up the two parts in 3D CAD I`d appreciate it, just for completeness of the entire project!

All the best.
Chris

[gingerneer]

Very nice craynerd. That's another project for the list.

William

[sbwhart]

Thats an interesting puzzle Chris

Thanks for showing.

Stew

[Stilldrillin]

I HATE that type of puzzles, and cubes! .......    Especially with the owner watching me struggle.....

That one's a cracker Chris! 

Blummin well done! 

David D

[raynerd]

OK guys, well I`ve taken it into work and no-one has yet managed to open it. Infact, no-one has even got close. I`m happy with the puzzle, it is tricky.

Now I`m getting a little obsessed. I`d like to make one even more difficult. I thought about some sort of thumb screw mechanism at the top. Perhaps something like a hollow shield going up the inside and covering the escape hole. So not only do the lid and base need aligning but also the thumb screw does as well. Anyway....more on that to come!

When this is polished is there anything I can do to keep the shine and stop it from scratching? Has anyone ever lacquered aluminium? I know I did a bit of anodizing in the "how to" forum but I want to keep it polished looking.

Any suggestions? 

[kwackers]

If nobody has managed to open it - how can you make it more difficult? 

[raynerd]

... huh ? No-one has managed to open my personal copy but others have opened cylinders of the same concept so the idea can surely be developed?

Any suggestions on the finish?


Chris

[madjackghengis]

Hi Chris, I would give it a high polish, and then spray it with a top quality clear coat which specifies aluminum, as some will not adhere well and start to flake off rather sooner than later.  Thanks for a great idea for Christmas presents, I've got a long bar of one inch brass which should do at least a half a dozen.  I wonder if it can be done with a cube?  I'm going to have to think on this one mad jack

[arnoldb]

Chris, that is a neat puzzle  - I think I'll annoy some accountant friends with it at some point... (beans should work instead of the balls - they can count them )

Scratches will always be a problem on any kind of polished surface IMHO, and especially so for a doodad such as this that will get handled a lot, so I'd venture a guess that for this puzzle a brushed and anodized finish might be the best.
You could make it out of stainless steel and polish that up - but even that will get scratched up with handling puzzling.

 , Arnold

[raynerd]

Hi Madjack - look forward to seeing your puzzle cubes! 
Arnold - yes I think scratches can`t be avoided. I`m too happy with it to risk ruining it by varnishing it in any way. I think I`ll make a second and then perhaps give that a go!

Anyway, MarkII has started with an additional part needed for the solution!

[j45on]

Great job I love puzzles like this and now I am going to have to make one    but I can only find 9.5mm BB's at the moment
Sorry a bit  I have also toyed with making a aluminium and brass version of this http://www.pacificpuzzleworks.com/22310 but would not know how to mill a egg shape 

[Dave Sohlstrom]

Chris

Here you go.

[raynerd]

Excellent!! I really really apreciate that, thanks a lot!!

What programme was that made in?     

Thanks again
Chris

[Bogstandard]

The only real way to protect the surface finish on aluminium so that it doesn't look bad is to engine turn or anodise it.

With engine turning, even though it will darken, it will not show fingerprints or small scratches, and will look presentable for years. The same sort of effect can be obtained by very fine knurling.

Anodising actually puts a hard oxide coating onto the surface, it is that which gives the protection. Plus you can colour it with easily obtainable Dylon fabric dyes.

Because ali forms a new oxide layer as soon as the old one is pentrated or worn off, unless you get some etch primer on there, to anchor onto the surface, followed by paint or laquer, it is almost guaranteed to peel off.


Bogs

[raynerd]

Hi John

Thanks for the info. Yes I had a go at anodising last year, around this time:

http://madmodder.net/index.php?topic=2441.0

I found my method worked ok but it did dull it down due to the oxide layer and I just really fancied keeping the mirror finish that I have now got! I guess I`ll have to live with it oxidising and my dad will have to keep it polished! I`ve run out of aluminium so the next one is brass anyway.

OK, thanks again
Chris

[Majorstrain]

Top puzzle Chris, 

I made one tonight out of steel, had it knocked over in about 3 hours. Changed the size to suit 30mm stock and 5mm balls.
Works a treat, I'll drop it off the the guys in the mechanical workshop tomorrow at uni and drive them made.
 
Phil

[Dave Sohlstrom]

Chris

I drew it using Alibre 3D CAD software. You can download a free version from WWW.alibre.com

Dave

[crabsign69]

how about a pic of the tool and is there groves inside  nice puzzle

[shoey51]

what a great puzzle love it 

[raynerd]

Slowcoach - when you say - a quick render are they drawings or real things!!!!!!!! I thought you had made one but then when I saw your half red anodised one.... WTF 

Are you kidding me... that is computer generated images??

Majorstrain - glad someone has made one and it has worked for them to! Pictures needed!

[AdeV]

They're computer drawings! You can tell because, in the 1st pic with the super-shiny items, there's no sign of the camera...

I must admit, though, they are extremely good renders. I am most impressed.

[slowcoach]

Yep, all generated by computer. I just wish there was a key I could press, to convert them from the virtual world in to the real world 







Cheers
Rob 

[boatmadman]

This is brilliant and I want to make one, but, how do you drill a semi circular hole??

[Majorstrain]

This is brilliant and I want to make one, but, how do you drill a semi circular hole??

I transfered the piece to the mill and held it with a V block in the vice. Then I used a slot drill to do the holes.
I drilled the cap hole before parting it off so there was something substantial to grip in the V block.

Pics, when I get home later tonight.

Cheers,
Phil

[raynerd]

Yep - the same. Used my new V-blocks  and just held it in the vice on my mill. I only had an end mill so I went into it at full depth (5mm) very slowly until I took out the semi-circle for the hole. 

AdeV - AMAZING !!! Haha, my wife has just taken a look at the red one with my name engraved and even she was blown away!

Chris